The present invention relates generally to a rotary indicating device in use, for example, for wheel covers of a motor vehicle, indication boards of advertising apparatus, ornamental elements for toys, and the like, and more particularly to a rotary indicating device which comprises a base member having an indication surface, the indication surface including indicating regions formed thereon and representing desired images such as pictures, letters, marks and the like, the indication region being able to be viewed by an observer as a distinct or definite image due to the after image phenomenon of an observer's eyes during the rotation of the base member.
Generally, the image formed on a rotary device is not able to be visually recognized by an observer as a distinct image during the rotation of the rotary device. It will be readily seen that if such an image applied on the rotary device could be visually recognized by the observer as a distinct image, it will produce an improved ornamental efficiency.
From the above viewpoint, there has been conventionally provided a rotary indicating device, namely a wheel cover in use for motor vehicles, in Japanese Utility Model Laid-open Publication No. 133923/1974. The above wheel cover comprises a cover body, and an ornamental disc relatively rotatably mounted on the front surface of the body. The ornamental disc has a shaft concentrically extending from the rear surface thereof. The shaft passes through and is relatively rotatably supported by a journal mounted on the central portion of the body, and has, at its rear portion positioned beside the rear surface of the body, a weight for preventing the ornamental disc from rotating together with the body. Therefore, the image formed on the ornamental disc may be maintained in a static manner with respect to the cover body rotating together with the wheel of the vehicle, so that the image can be visually recognized by the observer who sees the advancing vehicle.
The known wheel cover as described above, however, has a disadvantage in that it is complicated in construction.
In order to eliminate the above disadvantage, the present inventors have provided such a rotary indication device as shown in FIG. 5, which is described in Japanese patent Laid-open Publication No. 43490/1983.
Referring to FIG. 5, there is shown the rotary indicating device or wheel cover having, at its front surface as the indication surface, an indication region 2 representing an image or a pattern "A B C". The indication region 2 comprises a plurality of elongated reflection faces 3 which are respectively inclined in the same direction and also at the same angle with respect to a standard plane perpendicular to a rotary axis of the rotary base member. A observer located at a predetermined position with respect to the rotary device can visually recognize, during the rotation of the rotary indication device due to the after image phenomenon, the image "A B C" of the indication region taking a predetermined rotated position each rotation of the rotary member.
With the rotary indicating device as described above, there is no problem when the rotational speed thereof is relatively high. However, when the rotational speed of the indicating device is relatively low, the after image phenomenon is not effective so that each image to be received by the observer once each rotation of the rotary base member is recognized by the observer as a plurality of separated images, namely as a very obscure image, not as one static image. In other words, the image repeatedly appears and disappears.